Fluid pumping or compression in micro-liter scale is critical for a variety of micro instrumentation applications, including chip-scale chromatography and mass spectroscopy. It is also a key component in micro-refrigeration systems for electronic cooling. In the past decade, various micro/meso pumps have been developed based on electrostatic actuation, but so far have not demonstrated sufficient single-stage pressure head or vacuum levels for these applications. For example, to achieve the highly desirable <76 torr vacuum for chip-scale ion trap mass spectrometers (ITMS), multi-stage configuration is necessary but limited by volume constraint.
Current micropumps are even less adequate for refrigeration (i.e. heat pump), where pressure differential of several bars are needed. On the other hand, conventional and macro scale mechanical pump designs are extremely difficult to implement in microscales, due to their complex configuration, difficulty in valve fabrication, friction, and leakage issues.
Accordingly, one advantage of the present invention is to provide a micropump or compressor that has higher pressure and increased flow capacity when compared to diaphragm pumps.
Another advantage of the present invention is to provide a pump that is feasible for microscale implementation.
Yet another advantage of this invention is that has a valve-less design and built-in timing.
Still another advantage of this invention is to provide a micropump that requires no special drive electronics, thus reducing the cost of the device.
Other advantages will appear hereinafter.